Borrowing above £5 million places you firmly in the private bank lending space, where mainstream mortgage rules no longer apply. These loans are typically associated with luxury homes, significant refinances, international relocations, or major asset acquisitions. But in 2025, securing a £5m+ mortgage requires far more than high income or strong credit. Private banks now look at a borrower’s entire financial ecosystem—assets, liquidity, income sustainability, global wealth structures and long-term financial plans.
Buyers in this segment often include entrepreneurs, private equity partners, executives, investors, and UHNW families. Their income is frequently complex, irregular, global, or derived from multiple sources. Traditional banks struggle to assess cases like these because standard income multiples and affordability models do not reflect the realities of sophisticated financial lives. For this reason, private banks operate with entirely different underwriting principles.
In Prime Central London and the upper tier of the UK property market, private banks remain the primary route for borrowers needing £5m–£20m+ mortgages. But approval requires careful financial presentation. Even exceptionally strong borrowers must demonstrate liquidity, stability, transparency and a clear repayment strategy. Without this, applications can become slow, expensive, or unsuccessful.
At Willow Private Finance, we structure high-value cases every day. From international clients with multi-currency earnings to investment professionals with carried interest and partners with fluctuating drawings, we understand the nuance required to secure private bank approval.
Private banks occupy a unique position in the mortgage market. Their underwriting is fundamentally different from high street lenders, which rely heavily on automated affordability models, basic income evidence and risk scoring. Once loans exceed £3m–£5m, mainstream lenders become cautious, and many will not lend without restrictive terms, reduced LTVs or detailed affordability stress testing.
Private banks, by comparison, employ relationship-driven, asset-backed, and discretionary underwriting. They analyse the entire financial picture rather than isolating salary or dividends. This allows them to accommodate entrepreneurs, partners, investors and global earners whose wealth does not fit into rigid formulas.
Private banks in 2025 are also influenced by global regulatory expectations. Source-of-wealth checks, AML procedures, and cross-border financial assessments are more thorough than ever. London remains an international wealth hub, but increased scrutiny means borrowers must provide clear documentation for global assets, corporate ownership, and offshore arrangements.
Furthermore, private banks specialise in understanding the luxury property market. Homes above £5m often require a valuation approach that considers limited comparables, unique features, and long-term liquidity. Private banks tend to commission valuers familiar with super-prime assets, providing more consistent assessments than mainstream lenders.
Private bank underwriting is holistic. Rather than relying on a single affordability calculation, they examine four key pillars: liquidity, sustainability of income, total wealth position and clarity of financial structure.
Liquidity is at the centre of large mortgage approvals. Private banks want assurance that borrowers can service the loan even during market volatility or years with reduced income. This typically requires demonstrable access to cash or liquid investments. In the £5m+ space, private banks expect liquidity in the seven-figure range, reflecting the scale of responsibility that comes with eight-figure borrowing.
Income assessment is more nuanced. Private banks analyse multi-year income profiles rather than snapshots. For private equity partners, hedge fund managers or investment professionals, they examine carried interest cycles, bonus histories, vesting schedules and projected distributions. For entrepreneurs, they focus on company profitability, cash reserves, stability of business model and long-term financial sustainability, rather than drawings alone.
The borrower’s total wealth position significantly influences approval decisions. Private banks prefer clients with diversified assets across property, investments, trust structures, international holdings or mature businesses. This demonstrates long-term resilience and reduces reliance on any one income source.
Clarity of structure is essential. Borrowers with offshore entities, complex corporate ownership, trusts or multi-layered asset structures must provide documentation that traces wealth clearly and satisfies AML checks. Banks require visibility, not just numbers. Well-prepared documentation accelerates approvals, while ambiguity slows or blocks decisions.
Private bank mortgage structures are tailored, flexible and often linked to the borrower’s wider financial strategy. Interest-only terms are common, particularly for borrowers expecting future liquidity events such as bonus cycles, carried interest realisation, inheritance, asset sales or corporate distributions. These structures allow clients to preserve capital for investment rather than tie it up in amortisation.
Many £5m+ mortgages are designed around asset-backed underwriting. Lenders may consider investment portfolios, retained profits, global assets, and cash reserves when determining loan size and repayment terms. Private banks view these assets as evidence of financial strength, even if income patterns vary.
Cross-collateralisation is sometimes used for borrowers with multiple properties or substantial portfolios. For example, a borrower purchasing a £12m property may use equity in another asset to strengthen their profile and secure higher LTV.
Private banks also offer hybrid structures that blend interest-only borrowing with capital repayment plans aligned to future income events. This is particularly useful for investment professionals and entrepreneurs navigating variable earnings.
Some private banks require assets under management (AUM) as part of the lending relationship. This means the borrower places liquid assets with the bank in exchange for more favourable mortgage terms. While not always mandatory, AUM can unlock lower rates or increased flexibility. Understanding when and how to negotiate AUM is crucial for many borrowers.
Borrowers often underestimate the documentation and clarity required for private bank underwriting. High-level summaries are not sufficient. Banks require detailed wealth information, including investment statements, company accounts, international tax documentation and multi-year income history. Delays occur when borrowers are unprepared for the granularity required.
Income misinterpretation is another challenge. Borrowers with irregular income—private equity professionals, founders, consultants or global executives—may find their earnings misunderstood by lenders unfamiliar with non-linear income patterns. Without proper structuring and explanation, strong applicants can be incorrectly assessed.
Valuations are also a common friction point. Private banks rely on valuers experienced in super-prime homes. But even then, unique properties can produce conservative valuations, requiring loan restructuring or additional collateral.
Cross-border applicants face added complexity. Documenting international liquidity, sourcing foreign-held assets, proving residency, and navigating FX risk all require meticulous preparation.
The strongest applications present a clear and coherent financial narrative. This involves preparing a complete summary of personal wealth, income patterns, investments, liabilities, corporate positions and long-term financial plans. The clearer the information, the more confident the underwriters become.
Income narratives should reflect real-life patterns rather than strict annualised figures. This means explaining how carried interest flows, how business profits accumulate, how income is reinvested, and how fluctuations are absorbed by liquidity reserves. For many borrowers, accountants’ letters, projections, and consolidated financial summaries are essential.
Liquidity must be demonstrated with precision. Private banks need to know where funds are held, how quickly they can be accessed, and how they contribute to financial stability. Borrowers with diversified portfolios—property, equities, cash, international assets—should evidence each component.
Preparing for valuation issues is equally important. For large or unique homes, early valuation guidance can prevent shocks. Willow frequently coordinates informal discussions with valuers ahead of formal instruction, ensuring realistic expectations.
Finally, borrowers considering AUM-based lending should understand how this affects overall financial planning. For some, moving investments to a private bank offers strategic benefits. For others, it may be unnecessary. Expert negotiation often determines whether AUM becomes obligatory or optional.
A private equity partner purchasing a £14m property secured a £9m mortgage after demonstrating consistent carried interest distributions over a multi-year period and maintaining more than £2m in liquid assets. The bank approved interest-only terms tied to forecasted liquidity events.
A global entrepreneur with moderate salary but substantial company profits secured an £8m facility using a hybrid structure supported by retained earnings, investment portfolios and offshore liquidity. Clear documentation was critical.
An international UHNW family purchasing a £10m London home obtained private bank approval after presenting fully traceable source-of-wealth documentation, multi-jurisdictional income evidence and a strategic AUM commitment that unlocked preferential rates.
These examples illustrate how private banks use flexible underwriting when borrowers present clear, strategically structured financial cases.
Private bank lending remains robust. Despite regulatory tightening, banks continue to compete for high-value clients with diversified assets and strong long-term income prospects. Interest-only structures will remain dominant, while hybrid arrangements will grow as borrowers seek flexibility ahead of liquidity events.
London’s luxury property market continues to attract global capital, meaning demand for £5m+ mortgages is unlikely to slow. The key trend for 2025 is personalisation: banks will increasingly tailor lending terms to match the borrower’s wealth strategy, investments and global financial footprint.
Willow Private Finance specialises in securing £5m–£20m+ mortgages through private banks, international lenders and specialist institutions. We prepare lender-ready financial profiles that highlight liquidity, asset strength, long-term income sustainability and global financial stability. For clients with irregular income or multi-jurisdictional wealth, our structuring ensures lenders understand the full picture.
We negotiate AUM requirements, coordinate valuation strategy, manage complex documentation and position your case with the right lender from the outset. Our experience covering private equity partners, entrepreneurs, UHNW families, global executives and major investors ensures you secure the best terms available.
Q1: How much can you borrow with a private bank in 2025?
Private banks commonly lend between £5m and £20m+, depending on liquidity, assets and income sustainability.
Q2: What deposit is required for a £5m+ mortgage?
Most private banks lend at 60–70% LTV, though higher levels may be possible with strong asset backing or AUM commitments.
Q3: Do private banks accept bonus or carried interest income?
Yes. Private banks specialise in underwriting variable and performance-based income using multi-year averages.
Q4: Is AUM required for private bank lending?
Some banks require AUM, but many do not. AUM can be negotiated to improve rates or flexibility.
Q5: Can international income support a private bank mortgage?
Yes. With the correct documentation, private banks regularly approve mortgages based on foreign income.
Q6: How long does private bank approval take?
Most £5m+ mortgages take 6–12 weeks depending on documentation, valuation timings and compliance.
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About the Author
Wesley Ranger is the Director of Willow Private Finance and has more than 20 years of experience arranging complex, large-value mortgages for UK and international clients. His expertise includes private banking, asset-backed lending, high-net-worth underwriting and bespoke mortgage structuring. Wesley has supported hundreds of HNW and UHNW individuals in securing major property acquisitions and refinancing across Prime Central London and the wider UK.
Important Notice
This article provides general information only and does not constitute personal financial advice. Private bank lending for £5m+ mortgages involves bespoke underwriting, detailed financial assessment, source-of-wealth verification, AML checks and lender-specific criteria. Eligibility and terms depend on individual financial circumstances, liquidity, global income and regulatory requirements.
Always seek personalised advice before entering any financial arrangement.
Willow Private Finance Ltd is authorised and regulated by the Financial Conduct Authority (FCA No. 588422).
Registered in England and Wales.
